Stationary chimney vacuum cap



United States Patent Inventors Edward .I. Artis P. O. Box 7486, Boise, Idaho 83707;

Paul A. Artis, P. O. Box 7486, Boise, Idaho 83707 Appl. No. 767,222

Filed Oct. 14, 1968 Patented Aug. 11, 1970 STATIONARY CHIMNEY VACUUM CAP 3 Claims, 7 Drawing Figs.

U.S. Cl 98/78, 98/66 Int. Cl F23l 17/02 Field ofSearch 98/81, 78, 80,60, 66, 58,122

[56] References Cited UNlTED STATES PATENTS 293,526 2/1884 Scholl 98/66 391,503 10/1888 Betz 98/66 454,836 6/l89l Barnes 98/66 2,717,547 9/l955 Grenzebach et al 98/66 Primary Examiner- William E. Wayner Attorney-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT: A cap for mounting on the upper end ofa chimney or flue incorporating inner and outer generally spherical rows of slots so that when wind impinges on the cap, it creates a vacuum therein to enhance the exhausting and ventilating capabilities of the cap.

"Pgtente d Aug. 11,1970

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Paul A. Art/s INVENTORS Patented Aug. 11, 1970 Edward J. Ari/s Paul A. Arr/s INVENTORS BY M STATIONARY CHIMNEY VACUUM CAP Heretofore, the caps used on chimneys to exhaust and ventilate therefrom have been either of the rotary type or relatively complex stationary type. The rotary chimney cap requires a substantially balanced and carefully constructed cap to rotate on a hearing, which bearing must be kept relatively frictionfree so that the slightest breeze will cause the cap to rotate to accomplish the exhaust function. This ventilator, while very efficient, creates the problems of frozen or squeaky bearings and friction between the relatively movable parts which cause the slowing down or complete stoppage of the rotation of the chimney cap thereby completely defeating the purpose thereof. The fixed chimney cap while overcoming some of the problems of the rotary chimney cap have heretofore been an extremely complex device of louvers and deflector slats in a casing thereby creating a very costly installation.

The present invention relates to a cap for a chimney or flue that is fixed thereto to provide exhaust or ventilating capabilities. The device is comprised of a series of flat or planar slats which are arranged in spherical overlapping relationship so that wind-driven rain cannot pass therethrough and will deflect wind in a venturi-like action creating a partial vacuum in the interior thereof to enhance the exhausting and ventilating capabilities of the cap. The slats of the chimney cap are arranged in two concentric sphere-like layers with the venturi effect occurring between the two layers of slats.

lt is therefore an object of this invention to provide a cap for chimneys or flues that is fixed thereto'to exhaust or ventilate the chimney or flue.

It is a further object of this invention to provide a cap for a chimney or flue that is simple but unique in construction and having no relatively movable parts therein.

It is a further object of this invention to provide a cap for exhausting or ventilating chimney and flues that has two partial spheres in concentric relationship formed out of flat planar slats.

It is a further object of this invention to provide a cap for exhausting or ventilating chimneys that does not allow air or water to pass therethrough but directs the air back out of the cap creating a partial vacuum within the interior of the cap to enhance the exhausting and ventilating capabilities of the cap.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the vacuum cap installed on a flue.

FIGURE 2 is a sectional view taken substantially along the line 2-2 of FIGURE 1.

FIGURE 3 is a sectional view taken substantially along the line 3-3 of FIGURE 2.

FIGURE 4 is a top plan view of one of the slats that comprises the basic construction unit of the cap.

FIGURE 5 is a perspective view of another embodiment of the cap.

FIGURE 6 is a sectional view taken substantially along the line 6-6 of FIGURE 5.

FIGURE 7 is a top plan view of the basic construction unit of the cap shown in FIGURES 5 and 6.

Referring now to the drawings numeral 10 indicates a chimney or flue while the numeral 12 generally indicates the vacuum cap of this invention. The cap structure. 12 has a collar 14 to which is attached the substantially spherical shaped portion 16. v

The collar 14 of the cap is formed from a single flat sheet of metal or other appropriate material into a cylindrical portion or annular member that will fit telescopically over the chimney or flue 10. While the collar 14 is shown in a round configuration to coincide with the round chimney or flue 10 it should be understood that the lower end of the collar 14 can be shaped to fit any configuration of chimney or flue. The collar 14 has a lower or free end 18 thereof which is adapted and configured to fit over a chimney or flue, while the upper end 20 thereof has the spherical shaped cap portion 16 attached thereto.

The substantially spherical shaped portion 16 of the subject cap is constructed of a number of basic slat-like units 22, as shown in FIGURE 4. The unit 22 is an elongated flat or planar slat or strap with narrow tabs 24 at either end thereof. The unit 22 has a mid-section 26 which is narrower than the adjoining enlarged portions 28 but need not be as narrow as the tabs 24. The end tabs 24 of a width which is equal to onetwelfth of the circumference of the upper end 20 of the collar 14. The slat-like units 22 are each provided with an opening 30 in the center thereof. The units are arranged in an inner, generally spherical row of slats 32 and an outer, concentric and generally spherical shaped row of slats 34. The inner row of slats 32 comprises three of the basic slat-like units 22 in crossing relation with the openings 30 thereof receiving a bolt 36. The tabs 24 of these slats are then bent inwardly toward one another to form the general spherical shape of the inner row 32, with the tabs 24 being attached to the upper end 20 of the collar 14. With the slats being thus aligned apart and attached to the collar the tabs 24 will each cover approximately 30 of the circumference thereof and will have a space of approximately 30 of the circumference between them. The three basic slat-like units 22 with their six depending enlarged portions 28 thus form the inner generally spherical row of slats 32.

The outer row of slats 34 are composed of three slat-like units which are configured exactly like the units 22 but are slightly longer and are designated 22. The slight extra length of the slat-like unit 22 results in a larger circumference for the spherical unit 34 thereby making the rows 32 and 34 concentric. With the six slats forming the inner and outer rows 32 and 34 respectively, installed on the bolt 36 a nut 38 is installed thereon to secure the slats thereon.

With the slats thus arranged in the concentric rows 32 and 34 the inner slats 22 will close off the gaps left between the outer slats 22, as shown in FIGURE 3, thereby preventing wind or rain from entering the cap and penetrating through to the opening in the chimney or flue 10. As can be seen in FIGURE 3 a venturi-like chamber 40 exists between each slat 22 and the edges of the interior slats 22. The venturi-like chamber 40 has an enlarged opening 42 existing between each edge of the slats 22 and the overlapping inner adjacent edge of the slats 22. The narrow or mid-portion 42 of the venturi exists between the middle of the slat 22' and the adjacent edges of the inner slats 22. Thus wind approaching from any direction will enter the gaps between the slats 22' and impinge on the slats 22 to be directed through the venturi 40 creating a vacuum immediately inwardly of the inner row of slats 22 thereby enhancing the exhausting capabilities of the cap. As can be seen from the structure and its attachment in fixed relation to the chimney or flue, the efficiency thereof does not rely upon a spinning of the cap or high wind force. Further the overlapping of the slats 22 and 22 prevents wind and rain from entering thereinto to create dangerous downdrafts or corrosion due to the entrance of water.

The embodiment shown in FIGURES 5 through 7 is essentially the same as the embodiment of FIGURES l through 4 with the exception that the slat-like units are incorporated in basic units to reduce the number of parts needed to make up the cap. The cap 48 has a collar 14 identical to the collar 14 on the previous embodiments which cap has a lower or free end 18 whichis adapted to be received over and firmly engage a chimney or flue 10. The upper end 20 of the collar 14 is adapted to receive and have fixed thereto the basic units of the substantially spherical-shaped portion 50 thereof. The substantially spherical-shaped portion 50 is comprised of an inner sphere 52 and an outer concentric sphere 54. The inner sphere 52 is comprised of a basic flat unit 56 which hasa round circular center panel 58 with a hole 60 through the center thereof for receiving a fastener 61. Extending radially outwardly from the circumference of the circular portion 58 are a plurality of slats 62 spaced 60 apart. The slats 62 are similar to the enlarged portions 28 and tab portions 24 of the slats of the previous embodiment. The outer concentric spherical portion 54 is composed of a slat unit identical to the slat unit 56 and designated 56', The slat unit 56' has slightly longer slats 62' to provide for a larger concentric sphere 54 thereby making the spheres 52 and 54 concentric. The two slat units 56 and 56' are attached with the slats 62 and 62' in over lapping relationship, with their center lines spaced 30 apart, so as to present the same cross-section as shown in FIGURE 3. Thus, the resultant structure is identical in configuration and function as the embodiment of FIGURES 1 through 4 and can be conveniently constructed of only three basic units, which are the two basic slat units 56 and 56' and the collar 14.

The embodiment shown in FIGURES 1 through 4 can be comprised of any number of basic slat-like units 22 and 22' depending upon the circumference of the flue or chimney to be accommodated. Thus, it would be possible to have four or even five of the basic slat units form the inner and outer spherical rows of slats to accommodate an extremely large circumference chimney or flue. The embodiment shown in FIGURES 5 through 7 lends itself to pre-assembly in standard sizes in relatively low cost production due to the limited number of parts required to assemble the unit. The units being each constructed from flat sheet stock do not require any precise bending of parts to be used in the construction. Therefore, only average skill is required in the assemblying and construction of the cap and it can be sold as a kit to be assembled by the purchaser. Further, since the parts do not have to retain their shape in any precise bends they can be constructed out of any suitable sheet material such as plastic in addition to the common and well-known versions made out of sheet metal.

The ventilating and exhausting cap provided herein for chimneys is extremely simple in construction but a highly efficient unit that is extremely low in cost to produce and requires no routine maintenance and utilizes wind from any direction to enhance its evacuating properties. Further, even if the ventilator is used near a large perpendicular extending wall and wind impinging thereon strikes the ventilator in a direction opposite from the prevailing winds, this will not defeat the purpose of the ventilator but in fact will further add to and reinforce the evacuating capabilities of the cap.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

We claim:

1. A cap for a chimney or flue, comprising: an annular member, an inner, generally spherical row of spaced slats, an outer, generally spherical row of spaced slats in spaced concentric relation to said inner row, the slats in the inner row being aligned with the spaces between the slats in the outer row throughout the length of the spaces and the slats in the outer row being aligned with the spaces between the slats in the inner row throughout the length of the spaces, said slats having end portions anchored to said annular member, the inner and outer rows of slats being connected in overlying relation to each other remote from the annular member, each of said slats being flat from side edge to side edge thereof, the end portions of said slats anchored to said annular member and the portions of said slats connected in overlying relation being narrower than the portions of said slats intermediate the end portions and the overlying portions to assure overlapping of the slats in the outer row with the edges of the slats in the inner row, each row of said slats being constructed of sheet material to enable easy formation of the slats and assembly of the slats by bending longitudinally straight slats into the generally spherical rows of slats thus defining a generally spherical cap in which the annular member is adapted to telescope in relation to a chimney or flue for mounting thereon and the overlying portions of the slats are remote from the annular member and generally forms a cap above the annular member.

2. The device of Claim 1 wherein each row of slats includes a plurality of elongated, relatively narrow straps crossing each other at the center with the end portions attached to said annular member, means securing the crossed centers of the straps together for retaining the rows of slats assembled, the slats in the outer row being longer than the slats in the inner row thereby spacing the rows apart.

3. The device as defined in Claim 1 wherein each row of slats includes a central panel having a plurality of straps of equal length radiating therefrom with the free ends attached to said annular member, means securing the central panels together in overlying relation, the straps in the outer row being longer than the straps in the inner row thereby spacing the rows apart. 

